The present disclosure relates to an exposure control unit and an exposure controlling method in which an aperture diaphragm is variably controlled to obtain an apodization effect, and an image pickup unit.
There is known a method of improving contrast of an image by providing, to an entrance pupil of an optical system, an apodization filter with transmittance high at its center and gradually decreasing toward its periphery. Moreover, there is a method of obtaining an effect (apodization effect) approximating to the apodization filter by variably controlling an aperture diaphragm. For example, Japanese Unexamined Patent Application Publication Nos. H10-333202 (refer to FIG. 2) and 2004-317650 propose a method of obtaining the apodization effect by closing an aperture diaphragm to a predetermined initial value in advance at the start of an exposure period and gradually opening the aperture diaphragm during exposure.